From a viewpoint of saving water and washing of a bowl inner surface, many flush toilets configured such that washing water flows down on the bowl inner surface toward a drainage outlet portion in a bowl bottom portion as a swirling flow, have been provided. Also, although the bowl is, in general, constituted by left and right inner wall surfaces having the same curved surface, a flush toilet in which a valley groove that inclines downward toward the drainage outlet portion is provided closer to one of the left and right side in the vicinity of a bottom portion of the bowl, has also been provided (JP 2013-79566A (hereinafter referred to as “Document 1”), for example). In the flush toilet described in Document 1, washing water that flows down on the bowl inner surface while swirling, smoothly flows into the drainage outlet portion through the valley groove, and therefore, even if the water amount of the washing water is small, a waste transport distance can be extended. However, users desire a flush toilet which is configured such that the water amount of the washing water can be further reduced, and also the bowl inner surface can be washed at lower water pressure.